This (as a few others have noted) is the purpose of a probationary period. That cuts both ways, of course -- while I have only seen one person who "failed" the

This (as a few others have noted) is the purpose of a probationary period. That cuts both ways, of course -- while I have only seen one person who "failed" their probationary period, I have myself left a job during my probationary period when it turned out to not be what I'd been promised. That's what the probationary period is for.